Assessing the role of surface heterogeneity on energy balance partitioning and land-atmosphere feedbacks

The transport of mass and energy between the surface and the atmosphere is impacted by surface heterogeneity across a range of different spatial and temporal scales. A direct mechanism for this is the partitioning of energy between the sensible and latent heat fluxes. We investigate this via a large eddy simulation and a regional climate model. Using a suite of large-eddy simulations with different length scales of surface heterogeneity, we show that more homogeneous surfaces (either very small or very large length scales relative to the boundary layer height) correspond with higher latent heat fluxes for the same net radiation values. This leads to a predictable change in scalar profiles within the boundary layer. Next, we investigated the impacts at larger scales via a regional climate model. We used a suite of runs focusing on the impact of soil moisture heterogeneity and model resolution. We show that changes in energy balance partitioning impact the feedback between soil moisture and convective precipitation both in terms of the temporal and spatial scales of surface-precipitation interactions. Implications including the routine monitoring of surface fluxes via satellite remote sensing are also discussed.